The invention is based on a fastening for a wiper mount as generically defined by the preamble to claim 1.
Such wiper mounts are used in particular in motor vehicles, for securing wiper systems to the body of the motor vehicle. The wiper mount includes a motor mount, which carries a wiper drive mechanism with a wiper motor and mounted on that a gear. A power takeoff shaft of the gear, as a rule via a crank and toggle links, drives cranks that are solidly connected to a drive shaft for each wiper. The drive shafts are supported in wiper bearings, whose bearing housings are secured to or formed onto the ends of the mount. The mount is secured to a vehicle body with rubber-elastic elements directly via the bearing housings or via fastening eyelets that are formed onto the bearing housing, the mount, and/or the motor mount. Such wiper mounts are known for instance from European Patent Disclosure EP 0 781 691 A1.
From German Patent DE 36 21 233 C2, a wiper blade is also known for cleaning curved windows of motor vehicles. To achieve a good outcome of wiping of a flat vehicle window, the wiper blade would have to be disposed such that its longitudinal center plane is perpendicular to the window when the wiper blade is relieved, and that a wiper lip, formed onto the wiper strip, merely touches the surface of the window. In spherically curved vehicle windows, the inclination of this longitudinal center plane to the window surface changes over the entire swept field. Moreover, the inclination of the longitudinal center plane also varies in the longitudinal direction of the wiper blade. Thus the optimal alignment in spherically curved vehicle windows during wiper operation can be attained only at individual points that migrate in the longitudinal direction of the wiper blade. Hence the deviations from the vertical, or normal to the vehicle window, which are measured in degrees of angle and are called normal deviations or normal errors, are greater in the more markedly curved side portions of the vehicle window than in the flat middle portions. The flexibility of the rubber wiper blade can compensate only partly for the normal deviation.
In practice, the requisite positioning angle of the wiper blade relative to the window and thus the normal error is usually accomplished by positioning the drive axes of the is wipers obliquely. The wipers thus assume a desired position that deviates from a perpendicular position relative to the vehicle window. The desired normal error is adjusted as a rule upon assembly of the wiper mount, by tilting the wiper mount relative to the vehicle window. To that end, at least one fastening point of the wiper mount on the vehicle body is adjustable.
According to the invention, in the vicinity of the third fastening point, contact faces of the wiper mount that face one another, on the one hand, and a retaining element secured nondetachably to the vehicle body, on the other, form an angle xcex4. Between the contact faces, a rubber-elastic element whose end faces correspond to the contact faces is fastened by means of a screw. Once the screw is loosened, the wedge-shaped rubber-elastic element can be adjusted between the contact faces of the wiper mount and of the retaining element in the direction of the inclination of the contact faces to one another in such a way that the spacing of the wiper mount from the retaining element changes. Since the wiper mount is elastically supported at the other fastening points, it is tilted about an imaginary axis through the other two fastening points, so that the wiper bearings solidly connected to the wiper mount assume a correspondingly altered angle to the vehicle window. Once the correct angle is set, the rubber-elastic element is tightened again by the screw between the contact faces of the wiper mount and the retaining element. For the adjustment and fastening, only a few components are accordingly needed. Moreover, this results in easy assembly and adjustment, with only one screw having to be loosened.
As a rule, the frictional engagement between the contact face of the wiper mount on the one hand and the contact face of the retaining element on the other and the respective end faces of the rubber-elastic element suffices to maintain the position once set. However, to improve the nonpositive engagement by means of a positive engagement, it is proposed in one feature of the invention that at least one end face of the rubber-elastic element comprises a hard material and with the associated contact face has a set of teeth meshing with one another, which extends transversely to the inclination of the contact faces. The set of teeth makes the adjusting process easier as well, since the angle can be varied in small, defined stages.
For the passage of the screw, the rubber-elastic element has an oblong slot, whose greatest length extends in the direction of the inclination of the contact faces. The longest possible adjustment path is thus achieved without overly weakening the cross-sectional area of the rubber-elastic element. Expediently, a guide sleeve of a hard material that engages the inside of the rubber-elastic part of the rubber-elastic element stabilizes the position of the rubber-elastic element transversely to the contact face, especially if the end face of the rubber-elastic element oriented toward the contact face is formed by a flange of the guide sleeve.